1. Field of the Invention
The present invention relates to a disk player for performing reproduction or recording with respect to magneto-optical disks or optical disks such as CD or DVD (hereinafter abbreviated to a disk), and particularly to a disk player in which strength of a clamper plate is increased.
2. Description of the Related Art
Conventionally, as a technique of a disk player, there is a technique described in JP-A-9-297951 and referring to its one example based on FIGS. 12 to 14, substantially L-shaped reinforcement portions 3a are formed by perpendicularly folding both side edges of a steel plate-made clamper plate 3 bridged along right and left directions AC, AD orthogonal to backward and forward directions AA, AB between wall parts 2a of both sides of a cabinet 2 in which a tray 1 for a disk D is retractably placed in directions of arrows AA, AB, and both ends of the clamper plate 3 are fixed in the wall parts 2a of both sides of the cabinet 2 by screws 4. In FIG. 13, numeral 5 is a clamper engaged in a guide hole 6 formed in the center of the clamper plate 3, and comprises a clamper body 5a, a pair of upper and lower flange parts 5b, 5c fastened in upper and lower ends of the clamper body 5a and a magnet 5d fastened on a ceiling surface of the clamper body 5a, and is formed up-and-down movably within a predetermined range by a clearance a between the clamper plate 3 and the lower flange part 5c. Numeral 7 is a turntable placed up-and-down movably inside the cabinet 2.
Referring to a loading procedure of the disk D, as shown by an imaginary line in FIG. 12, by retracting b the tray 1 based on a loading signal after putting the disk D on the tray 1 in a state of forward a, the disk D on the tray 1 is positioned in a state concentric with the clamper 5 and the turntable 7 as shown in FIG. 13. Next, the turntable 7 is moved upward through a through hole 1a of the tray 1 and thereby, a center protrusion 7a of the turntable 7 is fitted into a center hole Da of the disk D to lift the disk D and thereby, as shown in FIG. 14, the clamper 5 is pushed up by the disk D and the disk D is clamped by the clamper 5 and the turntable 7 and the disk D is rotated by the turntable 7 and thereby, information recorded on the disk D is read by an optical pickup (not shown).
In a static load test before shipment, as shown by the imaginary line in FIG. 12, a test bar 8 is randomly pushed on the clamper plate 3 and a predetermined load is imposed and thereby, it is checked whether or not the clamper plate 3 is deformed and it is confirmed that strength of its clamper plate 3 is a predetermined value or more.
In the conventional configuration described above, in order to increase strength of the clamper plate 3, the reinforcement portions 3a are formed in both side edges of its clamper plate, but the reinforcement portions 3a are only formed in substantially L shape by perpendicularly folding the both side edges of the clamper plate 3, so that the amount of increase in strength by the reinforcement portions 3a is relatively small. Thus, for example, a steel plate with a relatively large wall thickness t of about 0.8 mm is used as the clamper plate 3 to increase rigidity in the clamper plate 3, but this increases material cost due to use of the steel plate with the large wall thickness t and also narrows a clearance α of the clamper 5 by the amount of the large wall thickness t, so that it is necessary to increase a height of the clamper 5 in order to ensure its clearance α sufficiently and this results in upsizing of a disk player.
Thus, based on a technique described in JP-A-11-054949, as shown in FIG. 15, it is considered that substantially rectangular reinforcement portions 3b are formed by folding both sides of a clamper plate 3 plural times. However, as a result of this, strength can be increased with respect to loads of directions of F2 and F4 but strength cannot be much increased with respect to loads of directions of F1 and F3 due to a relatively large gap 9 inside the substantially rectangular reinforcement part 3b. Therefore, also in this case, it is necessary to increase rigidity in the clamper plate 3 using a steel plate with a relatively large wall thickness t.